The 22-year-old, who has spent his entire career at the Buenos Aires outfit and whose twin brother Ramiro still plays for River Plate, has penned a contract running until summer 2018 after moving for an undisclosed fee. At Benfica he will link up with compatriots Lisandro López, Ezequiel Garay, Eduardo Salvio, Enzo Pérez and Nicolás Gaitán.

Capped once at senior level by Argentina, in a September 2012 friendly against Brazil, Funes Mori said: "I'm very happy. I had the dream of playing for a big team like Benfica. They have many supporters and are the biggest club in Portugal."

Benfica will start in the UEFA Champions League group stage, but on Sunday they suffered an early Liga setback. Having only lost once, to FC Porto, last season, they were beaten in their 2013/14 opener 2-1 by CS Marítimo.

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